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  #1  
Old 08-19-2011
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Bacteria Neonatal meningitis microorganism virulence!

A 35-year-old woman delivers a newborn who develops meningitis. The mother has a streptococcus isolated from her
vagina. The organism agglutinates with antiserum directed against type B surface carbohydrate. The virulence of this
organism is related to a bacterial constituent that interferes with which of the following host phagocyte functions?

(A) Aggregation
(B) Chemotaxis
(C) Ingestion
(D) Intracellular killing
(E) Pseudopod formation
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  #2  
Old 08-19-2011
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Im pretty sure its S. agalactiae how it works im not sure about that. Im guessing D. intracellular killing
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Old 08-19-2011
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even i m guessing intracellular killing
it is definitely group b strep but how it evades killing searched all over couldnt find it
plz give d answer
Group B streptococci cause neonatal sepsis and meningitis. The main predisposing factor is prolonged (longer than 18 hours) rupture of the membranes in women who are colonized with the organism. Children born prior to 37 weeks' gestation have a greatly increased risk of disease. Also, children whose mothers lack antibody to group B streptococci and who consequently are born without transplacentally acquired IgG have a high rate of neonatal sepsis caused by this organism. Group B streptococci are an important cause of neonatal pneumonia as well.
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  #4  
Old 08-19-2011
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Default not the answer though!

found this on www.eMedicine.com, it however does NOT answer the question:

"The virulence is of S agalactiae is related to the polysaccharide toxin it produces. Immunity is mediated by antibodies to the capsular polysaccharide and is serotype-specific. Several serotypes are known—Ia, Ib, Ic, II, III, IV, V, VI, VII, and VIII".
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Old 08-19-2011
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Agglutination may be the answer but Aggregation is given....
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Old 08-19-2011
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Quote:
Originally Posted by drnrpatel View Post
Agglutination may be the answer but Aggregation is given....
I think aggregation maybe right, (in strep), prevents localization of bacteria by host. Ex. Streptolysin.
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  #7  
Old 08-19-2011
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(C) Ingestion
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  #8  
Old 08-20-2011
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I think its A
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  #9  
Old 08-20-2011
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my guess is capsule (usually the main virulence factor for meningitis) so C
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Old 09-18-2011
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what is the answer plz ?!!
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Old 09-18-2011
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Streptococcus virulence factor is M protein, which prevents opsonization & interferes with phagocytosis. So I think C.
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This question is taken from a nbme form and the answer is ingestion
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Old 09-18-2011
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(C) Ingestion
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  #14  
Old 09-18-2011
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B .chemotaxis
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Old 09-18-2011
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Ingestion is the right ans
it has capsule which prevent this. . .
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